Electric vehicles generally employ DC electric motors. The speed of the vehicle is changed by changing the rpm of the DC motor. The speed of the motor can be varied by varying the number of batteries connected to the motor. This can be done through a stepping or sequencing type of control, but at some point the maximum speed is reached. With a series or other appropriate DC motor speed can also be varied by placing resistance in parallel with the field winding of the motor. This is called field weakening. As the value of the parallel resistance is decreased, the speed of the motor will increase. In the present construction, a fixed resistor is switched in, that is, placed in parallel with the motor field winding at a certain speed. This, in effect, extends the top speed of the vehicle. A typical speed increase would be to increase the top speed of the vehicle from 13 mph to 20 mph when the resistor is placed in parallel with the field winding. In the past this has been accomplished by a mechanical governor or speed sensor which would close a switch to cause the resistor to be placed in parallel with the field winding of the motor. A second switch would open to remove field weakening if the vehicle speed went too high. Attention is directed to U.S. Pat. No. 4,090,114.